Terraform ile Infrastructure as Code: AWS Örnek Projesi

Terraform ile Infrastructure as Code: AWS Örnek Projesi

Manuel AWS Console click-click infrastructure oluşturmak 2025'te kabul edilemez. Infrastructure as Code (IaC) ile her şey versiyonlanabilir, tekrarlanabilir, review edilebilir.

Neden Terraform?

• Cloud Agnostic: AWS, Azure, GCP, DigitalOcean - hepsi tek tool
• State Management: Terraform mevcut infrastructure'ı biliyor
• Plan Before Apply: Değişiklikleri önizle
• Modular: Reusable modules, DRY principle

Örnek Proje: Production-Ready VPC

# main.tf
terraform {
  required_version = ">= 1.0"
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
  backend "s3" {
    bucket = "mycompany-terraform-state"
    key    = "prod/vpc/terraform.tfstate"
    region = "eu-central-1"
    encrypt = true
    dynamodb_table = "terraform-locks"
  }
}

provider "aws" {
  region = var.aws_region
  default_tags {
    tags = {
      Environment = var.environment
      ManagedBy   = "Terraform"
      Project     = var.project_name
    }
  }
}

# VPC
resource "aws_vpc" "main" {
  cidr_block           = var.vpc_cidr
  enable_dns_hostnames = true
  enable_dns_support   = true

  tags = {
    Name = "${var.project_name}-vpc"
  }
}

# Public Subnets
resource "aws_subnet" "public" {
  count                   = length(var.public_subnet_cidrs)
  vpc_id                  = aws_vpc.main.id
  cidr_block              = var.public_subnet_cidrs[count.index]
  availability_zone       = data.aws_availability_zones.available.names[count.index]
  map_public_ip_on_launch = true

  tags = {
    Name = "${var.project_name}-public-${count.index + 1}"
    Type = "Public"
  }
}

# Private Subnets
resource "aws_subnet" "private" {
  count             = length(var.private_subnet_cidrs)
  vpc_id            = aws_vpc.main.id
  cidr_block        = var.private_subnet_cidrs[count.index]
  availability_zone = data.aws_availability_zones.available.names[count.index]

  tags = {
    Name = "${var.project_name}-private-${count.index + 1}"
    Type = "Private"
  }
}

# Internet Gateway
resource "aws_internet_gateway" "main" {
  vpc_id = aws_vpc.main.id

  tags = {
    Name = "${var.project_name}-igw"
  }
}

# NAT Gateway
resource "aws_eip" "nat" {
  count  = var.enable_nat_gateway ? length(var.public_subnet_cidrs) : 0
  domain = "vpc"

  tags = {
    Name = "${var.project_name}-nat-eip-${count.index + 1}"
  }
}

resource "aws_nat_gateway" "main" {
  count         = var.enable_nat_gateway ? length(var.public_subnet_cidrs) : 0
  allocation_id = aws_eip.nat[count.index].id
  subnet_id     = aws_subnet.public[count.index].id

  tags = {
    Name = "${var.project_name}-nat-${count.index + 1}"
  }
}

# Route Tables
resource "aws_route_table" "public" {
  vpc_id = aws_vpc.main.id

  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.main.id
  }

  tags = {
    Name = "${var.project_name}-public-rt"
  }
}

resource "aws_route_table" "private" {
  count  = length(var.private_subnet_cidrs)
  vpc_id = aws_vpc.main.id

  route {
    cidr_block     = "0.0.0.0/0"
    nat_gateway_id = var.enable_nat_gateway ? aws_nat_gateway.main[count.index].id : null
  }

  tags = {
    Name = "${var.project_name}-private-rt-${count.index + 1}"
  }
}

Best Practices

1. Remote State Backend

State file S3'te, DynamoDB lock ile. Team collaboration için şart.

2. Variables ve Outputs

# variables.tf
variable "environment" {
  description = "Environment name"
  type        = string
  validation {
    condition     = contains(["dev", "staging", "prod"], var.environment)
    error_message = "Environment must be dev, staging, or prod."
  }
}

3. Modules

Reusable infrastructure components. DRY principle.

4. Pre-commit Hooks

# .pre-commit-config.yaml
repos:
  - repo: https://github.com/antonbabenko/pre-commit-terraform
    hooks:
      - id: terraform_fmt
      - id: terraform_validate
      - id: terraform_tflint

CI/CD Integration

# .gitlab-ci.yml
terraform:plan:
  image: hashicorp/terraform:latest
  script:
    - terraform init
    - terraform plan -out=tfplan
  artifacts:
    paths:
      - tfplan

terraform:apply:
  image: hashicorp/terraform:latest
  script:
    - terraform init
    - terraform apply tfplan
  when: manual
  only:
    - main

Sonuç

Terraform ile infrastructure versiyonlanabilir, testable, reproducible hale gelir. Devups ile IaC migration başlayın.